Internal expansion pipe wrench



Sept. 20, 1 949. J RA I 2,482,501

INTERNAL EXPANSION WRENCH Filed Aug. 2, 1946 INVENTOR JUL/U6 R. ORAVETZ BY [MM- @4- ATTORN EY Patented Sept. 20, 1949 f. SUNITED STATES PATENT OFFICE I 2,482,501 INTERNAL EXPANSION PIPE WRENCH Julius R. Oravetz, New York, N. Y. 7 7

Application August 2, 1946, Serial No. 688,023

. ZOlainis. (01.81 12) This invention relates to pipe wrenches and is directed more particularly to a wrench which may be inserted into a pipe nipple, spud or other threaded connection or fitting, and, when operated, will grip the interior surface thereof in order to allow such pipe or fitting to be screwed on or removed from an adjacent part of a piping system.

The primary object of the invention is to provide a simple, efiicient and rugged construction, all parts of which are normally maintained in assembled relation and which, in use, will grip the pipe or fitting firmly, without serious damage thereto particularly if engaged with the threads of the pipe or fitting.

A further object of the invention is to provide a, wrench which will operate within fittings and connections of widely varying sizes without requiring any change in the parts of the wrench or the substitution of any parts, and beyond which scope of sizes, parts of other size may be substituted in the wrench to adapt it to therewith. 7

Another object of the invention is to so construct an internal wrench that it may be operated either to connect or disconnect pipe fittings or connections, i. e., to impart rotation to such fittings or connections in either clockwise or counterclockwise directions, as may be desired.

Speaking generally, the wrench of this invention comprises a spindle, one end of which has an appropriate handle, while near its other end, said spindle is provided with a cam rigid with the spindle and extending longitudinally thereof. At the opposite ends of the cam, links are pivoted intermediate their ends to the spindle and carry at their ends pivoted arcuate jaws. The interior surfaces of the jaws are arcuate to coact with the cam for the purpose of spreading the jaws, and their external, arcuately shaped surfaces are serrated, so that they may be brought into contact with the interior of a pipe or fitting and forced to a firm grip therewithby the cam when the spindle is turned.

The jaws are pivoted to the links adjacent one longitudinal edge of each jaw, i. e., their leading edges, and the free edges, i. e., their trailing edges, are forced outwardly through the operation of the jaws. By this construction the wrench is adapted to cooperate with pipe diameters of widely varying sizes.

The jaws are removably mounted on the links,

soas to permit them to be reversed when it is cooperate desired to reverse the direction of operation of the wrench or to permit smaller or larger jaws to be substituted in the event the pipe sizes to be operated upon so require, all as more specifically set forth in the following detailed description.

Features of the invention, other than those adverted to, will be apparent from the hereinafter detailed description and appended claims, when shown in phantom.

In the accompanying drawings, I indicates the spindle of the wrench. Its handle end is squared for cooperation with a handle 2, provided with two square holes into which the squared end of the wrench is adapted to fit. One hole is preferably provided at one end of the handle, while the other hole 3 may be intermediate the ends, as shown in Figure 2. Either hole may be used, depending upon the leverage required, or, if great leverage is necessary, a length of pipe may be slipped over the handle I and used to increase the leverage as is commonly done in manipulating plumbers wrenches.

a The head end of the spindle I carries a cam 4 which may be integral with the stem or attached thereto in any suitable way, but it should be rigid with the spindle. The'cam is of oval cross section and it is arranged symmetrically about the axis of the spindle i and coaxial therewith. Be-

yond the end of said cam is formed a boss 5 which constitutes, in effect, an extension of the spindle and terminates in a reduced coaxial threaded The link 1 carries near its opposite outer ends two jaw supporting pins [0. These pins are secured by a forced fit, threads, welding or otherwise, to the link I and they extend in parallel relation to each other and to the axis of the spindle, alongside of the cam and project into holes H provided therefor in the link 8, without attachment within said holes. A wing nut I2 is screwed on to the threaded post 6 and normally holds the. link 8 against, backing off the. ends of said pins.

Mounted on the pins IE1 intermediate the links 8 and 9 are two gripping jaws it. These jaws are generally of arcuate cross: section and of a length corresponding to the length of the cam. Each jaw is provided near its leading edge Ma with a longitudinal hole through which one. of

the pins passes, while the trailing edges I41) of the jaws are free, so that the jaws may bodily swing on said pins l0 (see Figs. 3 and 4). outer faces of the two jaws are roughened: so that they may more readily grip a pipe or fit..- ting, In thedrawings they are shown asserrated at I15, although they may be knurled, knobhed, or otherwise provided with sharp. edges or projections, well adapted.- for the gripping function.

As. shown, the outer surfaces of said. jaws are also provided with grooves. 18, so that the: wrench may be used inbushings; spuds, and the like, which frequently are provided with oppositely disposed internal ribs. or projecting keys. adapted to facilitate. their removah These channels. are intended for cooperation with such ribs orkeys and may either interlock directly therewith or provide sufficient clearance around the keys to :7

cave arcuate shape for cooperation with the cam 4 and through rotation oi the cam, while; the jaws remain relatively stationary; these jaws may be collapsed or spread. When, the, wrench is to be inserted intoa pipe or fitting, the spindle is turned so as to permit the jaws tocollapse or move toward one another, so thatthe. parts occupy the position indicated in Figure 3.. With the parts in this relation, the head of the, wrench may be readily inserted into. a pipe shown in phantom in Figure 3-. If-the. jaws are then held stationary, while the spindle is, rotated in, e. g., the clockwise direction indicated in Figure 4,, the cam will act againstv the. inner surfaces l! of the jaws to swing them outwardly and. into, engagement the pipe, as, shown in Figure 4 Atter this has been accomplished, continued rota,- ticn of the wrench will. cause the; jaws to. grip and rotate the pipe or other connection, as the case may be, and the greater the, rotating, pressure, thev greater will be the grip on the pipe.

Thus when the wrench is in the operation, of rotating the pipe to; attach or detach. the latter, the whole. wrench bodily rotates. with. the lJ-iueted edges of the jaws moving. in advance or leading the. remainders; of the jaws; while. the. free; edges of said jaws trail behind. Thus the pivoted edges of the jaws may be graphically referred to. as the leading edges, while the opposite edges of such jaws may be referred to as the trail.i-'ng edges. I

In the drawings; the jaws are so positioned as to adapt them to grip and rotate the pipe or fitting in a counterclockwise direction, i. e., in a direction to unscrew a right hand thread.

The

Should it be desired to reverse this operation, i. e., to screw in a right hand thread, the wing nut [2 may be removed, the link 8 withdrawn and the jaws l5 slipped ofi of the pins l0, reversed and returned to the pins. If the link 8 and wing nut I2 are then replaced, the parts will be in condition for operation of the wrench in a counterclockwise direction.

By pivoting each of the jaws along its leading edge, relatively little movement of the cam will effect relatively great movement of the trailing edge of the jaw and consequently the wrench is adapted to operate within widely different diameters. Inthe event, however, that pipes of greater diameter are encountered, the jaws shown in the drawings may be removed by removing the wing nut. and link 8 and larger or thicker jaws may be substituted in order to handle the larger diameters.

The wrench of this invention is extremely rugged. It will withstand tremendous; strains without breakage and yet. they parts are not, in themselves heavy. They are, however; so posed that, during the actual gripping and. turning operation, the cam jambs the jaws against the interior surfacev of the. pipev andthereafter there is very little strain on the pins. M or on. any other part of the structure since then practically all the strainis, taken by the. spindle, and its integral cam- At all other times, the links nevertheless hold the. jaws. in assembled relation with respect to the cam and spindle, so thatthe-y. can.- not. inadvertently fall. into. a, pipe: and become lost or clog the pipe. Nevertheless. these. parts may be readily dismantled for thepurposes stated when desired.

The foregoing detailed. descriptionsets forth the invention in its. preferred practical form. but the invention is to. be understood as. fully corn.- mensura te. with the appended claims.

Having thusv fully describedthe invention, what I claim as new and. desire. to, secure by Letters Patent is:

1. An internal pipe wrench comprising a spindle provided, near one end with a. cam,, p'iv.- oted to the spindle. intermediate. their ends. at the opposite ends of the cam, parallel pins car.- ried by and extending between. said Links, and gripping jaws. with. one longitudinal edge of. each jaw pivoted on. one oi said pins and the other longitudinal edge being free, the inner iace. of each jaw being concave for cooperation with the cam and the outer face of: each jawbeing roughened for gripping: engagement. with a pipe- 2'. An internal pipe wrench provided. with a spindle, near one end of which is. rigidly carried a cam substantially oval cross. section a1; ranged longitudinally of thespindleand coaxially thereof, a li-nh pivotal-1y mounted. coaxi-all-y of the spindle at each end of the cam. intermediate the ends of the, Links, meansv locking the. link at one or" against backing away from the cam and; the. link at the'otheir end 'of the cam being locked against backing away firomsaid last named end of the earn by a threaded member to the free of the spindle, pins anchored in the link at said one end of the cam extending" parallel toone another and to the axis of the spindle to and through perforations in the link at the other end of the cam, and jaws pivotally supported on. said 'pins' be;- tween said links, with the inner surfaces-of the jaws. being concave to cooperate with the cam and thei p pfi e gagingsurfaces of the jaws ber 6 ing roughened to grip the interior surface of 9. UNITED STATES PATENTS pipe. 7

JULIUS R. ORAVETZ. Number Name Date 1,251,408 Murray Dec. 25, 1917 REFERENCES CITED 5 FOREIGN PATENTS The following references are of. record in the r file of this patent: Number Country Date 118,085 Great Britain Oct. 31, 1918 

